See list attachedFebruary 26, 196969-PA-T-35APA/Chief, Apollo Data Priority CoordinationF/G Mirror Image Targeting shall use a three-minute delay
As you know, we have established as a standard procedure during Apollo rendezvous having CSM backup LM maneuvers in order to retain the nominal relative motion during this critical mission phase. On the D mission these “mirror image” CSM maneuvers are targeted with TIG delayed one minute after the LM TIG. One minute was chosen based on our estimate that it would be adequate for the crew to determine whether or not the command module should go active and to take the proper steps subsequent to that decision. John Young – the F mission CMP – was concerned that by using a one-minute delay he is forced to turn on his SPS trim gimbal motors for each of the mirror image maneuvers whether he has to execute the burn or not. Since there is no significant disadvantage in making the delay larger, we are changing it to three minutes for the F and G missions in order to avoid having to turn on those motors unnecessarily. Henceforth, all F/G analyses, simulations, procedures, and techniques will be based on that value.